arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2407.14749cs.RO
收藏

用于足式机器人跳跃动作的变频模型学习与预测控制

Variable-Frequency Model Learning and Predictive Control for Jumping Maneuvers on Legged Robots

University of Southern California(南加州大学);University of California San Diego(加利福尼亚大学圣迭戈分校);Kuwait University(科威特大学)

Chuong Nguyen, Abdullah Altawaitan, Thai Duong, Nikolay Atanasov, Quan Nguyen

AI总结:

针对足式机器人长飞行阶段动态跳跃动作精度与鲁棒性不足的问题,提出结合变频模型学习与变频MPC的控制方法,经硬件实验验证,跳跃距离误差显著降低,在不平地形也表现优异。

摘要:

在包含长飞行阶段的动态动作(如跳高或跳远)中同时实现目标精度和鲁棒性,一直是足式机器人面临的重大挑战。为解决这一难题,我们提出了一种新颖的基于学习的控制方法,该方法由模型学习和采用变频方案的模型预测控制(MPC)组成。与现有MPC技术相比,我们直接从实验中学习模型,不仅考虑了腿部动力学,还考虑了建模误差以及硬件层面和接触过程中未知的动力学失配。此外,通过变频方式学习模型,我们能够覆盖整个飞行阶段和最终跳跃目标,从而提升跳跃轨迹的预测精度。利用所学习的模型,我们还设计了变频机制以有效利用不同的跳跃阶段,精准跟踪目标。在Unitree A1机器人硬件上进行的共92次跳跃实验中,我们验证了所提方法的性能优于其他采用固定频率或标称模型的MPC,将跳跃距离误差降低了2至8倍。在带有随机放置、高度随机(最高达4厘米,即机器人站立高度的27%)扰动的不平坦地形上进行连续跳跃时,我们的方法实现了小于3%的跳跃距离误差。在34次具有不同跳跃目标和模型不确定性的单次及连续跳跃中,我们的方法取得了1至2厘米的距离误差。代码可在https://github.com/DRCL-USC/Learning MPC Jumping获取。

英文摘要:

Achieving both target accuracy and robustness in dynamic maneuvers with long flight phases, such as high or long jumps, has been a significant challenge for legged robots. To address this challenge, we propose a novel learning-based control approach consisting of model learning and model predictive control (MPC) utilizing a variable-frequency scheme. Compared to existing MPC techniques, we learn a model directly from experiments, accounting not only for leg dynamics but also for modeling errors and unknown dynamics mismatch in hardware and during contact. Additionally, learning the model with variable-frequency allows us to cover the entire flight phase and final jumping target, enhancing the prediction accuracy of the jumping trajectory. Using the learned model, we also design variable-frequency to effectively leverage different jumping phases and track the target accurately. In a total of 92 jumps on Unitree A1 robot hardware, we verify that our approach outperforms other MPCs using fixed frequency or nominal model, reducing the jumping distance error 2 to 8 times. We also achieve jumping distance errors of less than 3 percent during continuous jumping on uneven terrain with randomly placed perturbations of random heights (up to 4 cm or 27 percent the robot standing height). Our approach obtains distance errors of 1 to 2 cm on 34 single and continuous jumps with different jumping targets and model uncertainties. Code is available at https://github.com/DRCL-USC/Learning MPC Jumping.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑